[VOTE] 4.1.0 RC3

[Mickael Maison]

Hello Kafka users, developers and client-developers,

This is the 4th candidate for release of Apache Kafka 4.1.0.

The release brings many new features and improvements:
- Mechanism for plugin to register metrics
- Allow running multiple versions of connector plugins
- Queue are now in preview access
- New Streams rebalance protocol in early access
- Support for OAuth jwt-bearer grant type
- Improved metadata replication

Release notes for the 4.1.0 release:
https://dist.apache.org/repos/dist/dev/kafka/4.1.0-rc3/RELEASE_NOTES.html

*** Please download, test and vote by Monday September 1

Kafka's KEYS file containing PGP keys we use to sign the release:
https://kafka.apache.org/KEYS

* Release artifacts to be voted upon (source and binary):
https://dist.apache.org/repos/dist/dev/kafka/4.1.0-rc3/

* Docker release artifacts to be voted upon:
apache/kafka:4.1.0-rc3
apache/kafka-native:4.1.0-rc3

* Maven artifacts to be voted upon:
https://repository.apache.org/content/groups/staging/org/apache/kafka/

* Javadoc:
https://dist.apache.org/repos/dist/dev/kafka/4.1.0-rc3/javadoc/

* Tag to be voted upon (off 4.1 branch) is the 4.1.0 tag:
https://github.com/apache/kafka/releases/tag/4.1.0-rc3

* Documentation:
https://kafka.apache.org/41/documentation.html
PR (https://github.com/apache/kafka-site/pull/702) updated for RC3 is
not merged yet

* Protocol:
https://kafka.apache.org/41/protocol.html
PR (https://github.com/apache/kafka-site/pull/702) updated for RC3 is
not merged yet

* Successful CI builds for the 4.1 branch:
Unit/integration tests: https://github.com/apache/kafka/actions/runs/17263427471
System tests: Tests are currently running, I'll post the results once
they complete

* Successful Docker Image Github Actions Pipeline for 4.1 branch:
Docker Build Test Pipeline (JVM):
https://github.com/apache/kafka/actions/runs/17263452575
Docker Build Test Pipeline (Native):
https://github.com/apache/kafka/actions/runs/17263456887

Thanks,
Mickael

[Mickael Maison]

Hi,

The docs PR has been merged so the documentation and protocol for 4.1 are up:
- https://kafka.apache.org/41/documentation.html
- https://kafka.apache.org/41/protocol.html

The system tests have completed.
I still got the network_degrade_test failure (tracked by
https://issues.apache.org/jira/browse/KAFKA-19549).
Also I reverted by mistake the temporary fix [0] I had made to the 4.1
branch for https://issues.apache.org/jira/browse/KAFKA-19581, so the
Streams upgrade tests failed in the results, but they pass locally.
- Core: https://drive.google.com/file/d/1-XdhozO1t78vWW4z127lweNa45DiYbmd/view?usp=drive_link
- Non core: https://drive.google.com/file/d/1BLydIgKGBsV6B0UtnKJMNKNwAgz0ABGy/view?usp=drive_link

0: https://github.com/apache/kafka/commit/de16dd103af93bb68a329987ff19469941f85cbc

Thanks,
Mickael

On Fri, Aug 29, 2025 at 12:54 PM Paolo Patierno
<paolo.p...@gmail.com> wrote:
>
> We ran all regression tests with Strimzi and everything looks good.
>
> +1 (non binding)
>
> Thanks,
> Paolo

> --
> Paolo Patierno
>
> *Senior Principal Software Engineer @ IBM**CNCF Ambassador*
>
> Twitter : @ppatierno <http://twitter.com/ppatierno>
> Linkedin : paolopatierno <http://it.linkedin.com/in/paolopatierno>
> GitHub : ppatierno <https://github.com/ppatierno>